This invention relates generally to deployable and generally dish-shaped structures of the type designed primarily for use as an antenna or the like in an outer space environment. More particularly, this invention relates to an improved deployable reflector which can be folded from a highly compact collapsed state to a deployed state of an expanded diametric size.
Collapsible and deployable dish-shaped structures in general are relatively well known and have been widely used in outer space applications to provide, for example, an antenna or the like for receiving and/or transmitting radio signals. Such collapsible structures advantageously can be stowed compactly in a space vehicle for launching into outer space and then deployed to the desired expanded dish-shaped configuration. Examples of such dish-shaped structures are found in U.S. Pat. Nos. 3,064,534; 3,176,303; 3,286,270; 3,360,798; 3,377,594; 3,383,692; 3,397,399; 3,617,113; 3,699,576; 3,717,879; 3,715,760; and 4,315,265.
In one common form, collapsible and deployable dish structures for space applications have been constructed from a network of lightweight frame components designed to support a flexible material having an electrically conductive reflective surface, such as a foil or the like. While such structures are well-suited for compact stowage for launching, deployment in outer space to the expanded dish-shaped configuration has not occurred with the desired degree of simplicity and reliability. Moreover, the flexible reflector material has not provided the requisite precision reflector surface geometries required for some high resolution and/or high frequency applications, for example, as may be required for a parabolic surface antenna.
Other known deployable dish structures have been constructed from rigid elements or panels to provide precision reflector geometries. However, the majority of such rigid dish structures have been undesirably complex in design and assembly, have not been collapsible to a satisfactorily compact state, and further have proven to be generally unreliable in deployment. Improved rigid dish structures designed for reliable deployment in space, such as those described in commonly assigned U.S. Pat. Nos. 3,715,760 and 4,315,265, have required relatively large stowage envelopes in relation to expanded diametric size thereby placing undue size limitations upon the dish structures when deployed.
There exists, therefore, a significant need for an improved dish-shaped structure designed particularly for use as an antenna or the like in an outer space environment, wherein the structure is collapsible to a highly compact state for stowage within the cargo bay of a space vehicle, and further wherein the structure is deployable in space quickly, easily, and reliably to an expanded state with satisfactory geometric precision. The present invention fulfills these needs and provides further related advantages.